PyQt5 using Drop_groupBox() from another file - drag-and-drop

Question

I have a groupBox in my PyQt5-Application which serves as a dropzone, where the user can upload files and the dropEvent prints a list of the filenames that were dragged into the dropzone and writes them to the listWidget. I have slightly changed the original code from here:
dropfiles.py
# -*- coding: utf-8 -*-
#
# Created by: PyQt5 UI code generator 5.6
#
# WARNING! All changes made in this file will be lost!
import os
from PyQt5 import QtCore, QtGui, QtWidgets
class Drop_groupBox(QtWidgets.QGroupBox):
dropped = QtCore.pyqtSignal(list)
def __init__(self, parent):
super().__init__(parent)
self.setAcceptDrops(True)
def dragEnterEvent(self, e):
if e.mimeData().hasUrls():
e.accept()
else:
e.ignore()
def dropEvent(self, e):
list_of_files = [url.toLocalFile() for url in e.mimeData().urls() if os.path.isfile(url.toLocalFile())]
self.dropped.emit(list_of_files)
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(658, 449)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
MainWindow.setSizePolicy(sizePolicy)
MainWindow.setMinimumSize(QtCore.QSize(658, 449))
MainWindow.setMaximumSize(QtCore.QSize(658, 449))
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayout_3 = QtWidgets.QGridLayout(self.centralwidget)
self.gridLayout_3.setObjectName("gridLayout_3")
self.gridLayout = QtWidgets.QGridLayout()
self.gridLayout.setObjectName("gridLayout")
self.label_Files = QtWidgets.QLabel(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.label_Files.sizePolicy().hasHeightForWidth())
self.label_Files.setSizePolicy(sizePolicy)
self.label_Files.setMinimumSize(QtCore.QSize(122, 20))
self.label_Files.setMaximumSize(QtCore.QSize(122, 20))
self.label_Files.setObjectName("label_Files")
self.gridLayout.addWidget(self.label_Files, 0, 0, 1, 1)
self.listWidget_Files = QtWidgets.QListWidget(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.listWidget_Files.sizePolicy().hasHeightForWidth())
self.listWidget_Files.setSizePolicy(sizePolicy)
self.listWidget_Files.setMinimumSize(QtCore.QSize(256, 341))
self.listWidget_Files.setMaximumSize(QtCore.QSize(256, 341))
self.listWidget_Files.setObjectName("listWidget_Files")
self.gridLayout.addWidget(self.listWidget_Files, 1, 0, 1, 1)
self.gridLayout_3.addLayout(self.gridLayout, 0, 0, 1, 1)
# self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
self.groupBox = Drop_groupBox(self.centralwidget)
self.groupBox.dropped.connect(self.fill_fileslist)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.groupBox.sizePolicy().hasHeightForWidth())
self.groupBox.setSizePolicy(sizePolicy)
self.groupBox.setMinimumSize(QtCore.QSize(300, 300))
self.groupBox.setMaximumSize(QtCore.QSize(400, 300))
self.groupBox.setTitle("")
self.groupBox.setObjectName("groupBox")
self.gridLayout_2 = QtWidgets.QGridLayout(self.groupBox)
self.gridLayout_2.setObjectName("gridLayout_2")
self.label = QtWidgets.QLabel(self.groupBox)
self.label.setObjectName("label")
self.gridLayout_2.addWidget(self.label, 0, 0, 1, 1)
self.gridLayout_3.addWidget(self.groupBox, 0, 1, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 658, 19))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "TestCase"))
self.label_Files.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:12pt; font-weight:600;\">Selected Files</span></p></body></html>"))
self.label.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:16pt; font-weight:600;\">Drop Files Here!</span></p></body></html>"))
def fill_fileslist(self, files_list):
self.listWidget_Files.addItems(files_list)
print(files_list)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
This works perfectly fine, when I have all the code in one file. But now my problem is that I am designing a gui with the PyQt Designer and I want to separate the "gui"-file from the file with the programming logic (programming functions), so that when I change something in the gui and convert it to a python file (with pyuic), the functions not defined in the Designer won't be overwritten. So this is what I have tried:
mainwindow.py (the gui file)
# -*- coding: utf-8 -*-
#
# Created by: PyQt5 UI code generator 5.6
#
# WARNING! All changes made in this file will be lost!
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
def setupUi(self, MainWindow):
MainWindow.setObjectName("MainWindow")
MainWindow.resize(658, 449)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
MainWindow.setSizePolicy(sizePolicy)
MainWindow.setMinimumSize(QtCore.QSize(658, 449))
MainWindow.setMaximumSize(QtCore.QSize(658, 449))
self.centralwidget = QtWidgets.QWidget(MainWindow)
self.centralwidget.setObjectName("centralwidget")
self.gridLayout_3 = QtWidgets.QGridLayout(self.centralwidget)
self.gridLayout_3.setObjectName("gridLayout_3")
self.gridLayout = QtWidgets.QGridLayout()
self.gridLayout.setObjectName("gridLayout")
self.label_Files = QtWidgets.QLabel(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.label_Files.sizePolicy().hasHeightForWidth())
self.label_Files.setSizePolicy(sizePolicy)
self.label_Files.setMinimumSize(QtCore.QSize(122, 20))
self.label_Files.setMaximumSize(QtCore.QSize(122, 20))
self.label_Files.setObjectName("label_Files")
self.gridLayout.addWidget(self.label_Files, 0, 0, 1, 1)
self.listWidget_Files = QtWidgets.QListWidget(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.listWidget_Files.sizePolicy().hasHeightForWidth())
self.listWidget_Files.setSizePolicy(sizePolicy)
self.listWidget_Files.setMinimumSize(QtCore.QSize(256, 341))
self.listWidget_Files.setMaximumSize(QtCore.QSize(256, 341))
self.listWidget_Files.setObjectName("listWidget_Files")
self.gridLayout.addWidget(self.listWidget_Files, 1, 0, 1, 1)
self.gridLayout_3.addLayout(self.gridLayout, 0, 0, 1, 1)
self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Fixed)
sizePolicy.setHorizontalStretch(0)
sizePolicy.setVerticalStretch(0)
sizePolicy.setHeightForWidth(self.groupBox.sizePolicy().hasHeightForWidth())
self.groupBox.setSizePolicy(sizePolicy)
self.groupBox.setMinimumSize(QtCore.QSize(300, 300))
self.groupBox.setMaximumSize(QtCore.QSize(400, 300))
self.groupBox.setTitle("")
self.groupBox.setObjectName("groupBox")
self.gridLayout_2 = QtWidgets.QGridLayout(self.groupBox)
self.gridLayout_2.setObjectName("gridLayout_2")
self.label = QtWidgets.QLabel(self.groupBox)
self.label.setObjectName("label")
self.gridLayout_2.addWidget(self.label, 0, 0, 1, 1)
self.gridLayout_3.addWidget(self.groupBox, 0, 1, 1, 1)
MainWindow.setCentralWidget(self.centralwidget)
self.menubar = QtWidgets.QMenuBar(MainWindow)
self.menubar.setGeometry(QtCore.QRect(0, 0, 658, 19))
self.menubar.setObjectName("menubar")
MainWindow.setMenuBar(self.menubar)
self.statusbar = QtWidgets.QStatusBar(MainWindow)
self.statusbar.setObjectName("statusbar")
MainWindow.setStatusBar(self.statusbar)
self.retranslateUi(MainWindow)
QtCore.QMetaObject.connectSlotsByName(MainWindow)
def retranslateUi(self, MainWindow):
_translate = QtCore.QCoreApplication.translate
MainWindow.setWindowTitle(_translate("MainWindow", "TestCase"))
self.label_Files.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:12pt; font-weight:600;\">Selected Files</span></p></body></html>"))
self.label.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:16pt; font-weight:600;\">Drop Files Here!</span></p></body></html>"))
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = Ui_MainWindow()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
dropfiles_functions.py (the file with the programming logic)
# -*- coding: utf-8 -*-
import os
from PyQt5 import QtCore, QtWidgets
from dropfiles_gui import Ui_MainWindow
class Drop_groupBox(QtWidgets.QGroupBox):
dropped = QtCore.pyqtSignal(list)
def __init__(self, parent):
super().__init__(parent)
self.setAcceptDrops(True)
def dragEnterEvent(self, e):
if e.mimeData().hasUrls():
e.accept()
else:
e.ignore()
def dropEvent(self, e):
list_of_files = [url.toLocalFile() for url in e.mimeData().urls() if os.path.isfile(url.toLocalFile())]
self.dropped.emit(list_of_files)
class MConv(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
QtWidgets.QMainWindow.__init__(self)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
self.ui.groupBox = Drop_groupBox(self.ui.centralwidget) # <-- why is this not working?
self.ui.groupBox.dropped.connect(self.fill_fileslist) # <-- why is this not working?
def fill_fileslist(self, files_list):
self.listWidget_Files.addItems(files_list)
print(files_list)
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = QtWidgets.QMainWindow()
ui = MConv()
ui.setupUi(MainWindow)
MainWindow.show()
sys.exit(app.exec_())
I don't understand why the drop event is not passed to the groupBox. In the file 'dropfiles_functions.py' I changed the 'self.ui.groupBox' to the 'new Drop_groupBox', but its funcitonaltiy is not working. Can someone please explain to me why this is the case and what I'm doing wrong?

Answer 1

In order to get this to work, you need to promote your groupbox widget in QtDesigner from a QtWidgets.QGroupBox to a Drop_groupBox widget. You can check the official Qt documentation to find out how. If you succeed and convert the .ui file to a .py file, the line
self.groupBox = QtWidgets.QGroupBox(self.centralwidget)
should have been replaced by
self.groupBox = Drop_groupBox(self.centralwidget)
and at the bottom of the .py file there should be an import statement similar to
from dropfiles_functions import Drop_groupBox
The next step is to correctly setup MConv. Since MConv inherits from both QMainWindow and Ui_MainWindow, you don't need to create a separate instance of Ui_MainWindow in QMainWindow.__init__. Instead you can refer to MConv.setupUi and MConv.groupBox directly, i.e.
class MConv(QtWidgets.QMainWindow, Ui_MainWindow):
def __init__(self):
super().__init__(self)
self.setupUi(self) # <-- this will define self.groupBox = Drop_groupbox(...) amongst others
self.groupBox.dropped.connect(self.fill_fileslist)
def fill_fileslist(self, files_list):
self.listWidget_Files.addItems(files_list)
print(files_list)
Finally, in the if __name__ == "__main__" block you need to make sure you are using an instance of MConv rather than a standard QMainWindow, i.e.
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
MainWindow = MConv()
MainWindow.show()
sys.exit(app.exec_())